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Biomedical subjects

D L Dyess

Publications and source records attributed to D L Dyess.

31 records · Page 2Linked to original sources
PubMed1990

Nonsurgical management of breast infections in nonlactating women. A word of caution.

UNLABELLED: Management options for infectious mastitis have traditionally been limited to surgical drainage. With the advent of percutaneous fine needle aspiration (FNA), nonoperative treatment may be an alternative, though criteria for use have not been defined. During a 30-month period, 22 women presented with breast infection. Treatment was instituted based upon the clinical stage of infection. Patients with cellulitis (n = 8) were managed with diagnostic FNA/antibiotics. Those with focal abscess (n = 10) underwent FNA of the cavity/antibiotics. Patients with multiloculated abscess (n C = 3) underwent urgent surgical drainage. Of the 19 patients initially treated nonoperatively, resolution occurred in nine (47%); stage of infection did not effect outcome. Surgical drainage was required in the remainder; two cancers were found. FNA cytology in these (and all) patients was negative for malignancy. All underwent mammography during treatment. In 17 (77%) cancer was considered of low probability. The only patient with a mammogram highly suspicious for cancer had fat necrosis on biopsy. Bacterial cultures were positive in 79 per cent, virtually all with Gram (+) cocci. Four patients harbored Gram (-) organisms as well, two in concert with breast cancer. CONCLUSIONS: 1) select breast infections can be successfully managed nonoperatively, 2) the accuracy of FNA and mammography in the diagnosis of breast cancer may be impaired by coincident infection, 3) the finding of a Gram (-) breast infection warrants abandonment of nonoperative management in favor of tissue confirmation of the disease process.

Abscess↗
PubMed1990

In vitro effects of complement inactivation upon burn-associated cell-mediated immunosuppression.

Serum of severely burned patients possesses in vitro capacity to suppress cell-mediated immunologic responses. Failure to establish immune competence is predictive of mortality, usually from sepsis. In this investigation, the hypothesis that complement fragments, known to be elevated in the acute phases of burn injury, contribute to this suppression is tested. Serum taken from patients with massive (greater than 60%) and major (less than or equal to 60%) burn injury was analyzed for the ability to suppress mitogen-induced lymphocyte blastogenesis before and after exposure of the burn serum to (complement inactivating) temperatures. All patients in this study had immune suppressive serum. Heat inactivation partially restored immune competence in the serum of all patients, though significantly more so in patients with major burns compared with those with massive burns. Complement appears to play a contributory role in the acute stages of burn-induced, cell-mediated immunosuppression, though its role in patients with massive burn injury is overshadowed by the presence of serologic suppressive factors not present (or present in lower concentration) in patients with major burns.

Adult↗
PubMed1988

Cholecystostomy. Expected outcome in primary and secondary biliary disorders.

Cholecystostomy is used for biliary-tree drainage when simplicity and speed are of prime importance. Its frequency of use and the subsequent mortality rates, vary among surgeons and institutions. This review analyzes 50 cholecystostomies performed over 6 years at one institution, and defines outcome as related to presenting symptoms. Twenty five patients (Group 1) presented with symptoms of acute cholecystitis, and underwent cholecystostomy. Twenty (80%) had gallstones and five (20%) were acalculous. Two patients died, a mortality rate of 8 per cent. Twenty five other patients (Group 2) developed signs suggesting cholecystitis during hospitalization for an unrelated illness. Only 50 per cent (13/25) of Group 2 patients were found to have cholecystitis at operation (eight calculous, five acalculous). Mortality was 62 per cent (8/13) in the Group 2 patients with inflammatory cholecystitis, and 50 per cent (6/12) for the patients with normal gallbladders. A positive outcome may be anticipated if cholecystostomy is used in patients admitted with acute cholecystitis who present too great a surgical risk for formal cholecystectomy. In contrast, the diagnosis of cholecystitis in the critically ill patient can be difficult and the prognosis for survival is not good, even after cholecystostomy.

Acute Disease↗
PubMed1988

Surface oximetry. A new method to evaluate intestinal perfusion.

Accepted methods to evaluate intestinal vascularity intraoperatively include standard clinical criteria (SCC), doppler ultrasound (DUS), and intravenous fluorescein (FLF). A combination of methods is often used to overcome disadvantages of individual techniques. Assessment of intestinal vascularity by FLF was compared to SCC, DUS, and pulse oximetry (POX) in segments of intestine demonstrating arterial, venous and arteriovenous occlusion, to determine if POX might supplement the assessment of intestinal vascularity. POX uses a commercially available instrument to assess tissue oxygenation and arterial flow, and is rapid, reproducible, and noninvasive. POX appears to be a superior technique when compared to SCC and DUS.

Animals↗
PubMed1986

The first 70 years experience managing cardiac disruption due to penetrating and blunt injuries at the University of Louisville.

Survival of patients with cardiac injuries requires prompt intervention and cardiography. Approximately 50 years ago, Dr. R. Arnold Griswold instituted a treatment plan for the management of cardiac injuries. Many of the tenets he espoused are still in use today. We have been able to collect data on 266 patients with heart wounds from 1913 to 1982 at Louisville General Hospital. Trends in the evolution of injury patterns and their treatment will be discussed.

Cardiac Surgical Procedures↗
PubMed1985

Candida sepsis. Implications of polymicrobial blood-borne infection.

Eighty-three patients with 117 episodes of candidemia were reviewed to examine the clinically significant variables and the results of treatment for this problem. Mortality was 52%. Patients who had bacteremia either synchronously or metachronously in association with Candida species had poorer survival rates. Staphylococcal and enterococcal species were the most frequently associated bacteria. Patients with Candida parapsilosis had better survival rates than patients with other species. Portals of entry for fungemia were catheters, wounds, the urinary tract, and the peritoneal cavity, but were undefined in 54% of patients. Antifungal chemotherapy could not be identified as affecting the outcome in these patients. It is suggested that candidemia in most patients represents a failure of host defense, and that septicemia of either bacteria or fungi may arise from the gastrointestinal tract in critically ill, immunocompromised patients.

Adolescent↗
PubMedDate not supplied

The suppressive effect of subeschar tissue fluid upon in vitro cell-mediated immunologic function.

UNLABELLED: Fluid administered during resuscitation translocates beneath the burn wound and is considered inert "third space" loss. This study was done to determine whether subeschar tissue fluid (STF) functions as an immunobiologic reservoir. Seven patients with a mean BSA burn of 55% underwent isotonic volume resuscitation and burn treatment with low penetration topical agents. STF was collected at the time of fascial excision. Chemical analysis of STF was similar to serum; bacterial cultures grew no organisms. Ten percent dilutions of STF and burn serum significantly blunted mitogen-induced blastogenic response compared to control serum. STF was significantly more suppressive than burn serum (P less than .03). CONCLUSIONS: 1. STF may act as both an immunologic barrier to microbial clearance in otherwise viable subcutaneous tissue and a reservoir for systemically reabsorbed immunosuppressive factors. 2. In addition to removing dead tissue, fascial excision may prove beneficial because it removes large amounts of immunosuppressive STF.

Adult↗
PubMedDate not supplied

Transportation of immunosuppressive substances produced at the site of burn injury into the systemic circulation: the role of lymphatics.

Serum of patients with severe burns has the ability to suppress mitogen-induced lymphocyte proliferation. Edema fluid collected from the site of injury during resuscitation and at the time of fascial excision has also been shown to suppress this response. An animal model was designed to identify the onset time of the formation of suppressive factors, their potential site(s) of origin, and their route of entry into the systemic circulation. Femoral artery, saphenous vein, and lateral saphenous lymphatic vessels were cannulated in an anesthetized dog. Baseline samples were collected, the hind paw was subjected to scald injury, and samples were collected serially for up to 6 hours after burn injury. Tissue fluid beneath the scald injury was harvested at the end of the experiments. In the absence of significant serologic evidence for inhibition, lymph and tissue fluid exhibited early and prolonged suppression of mitogen-induced lymphocyte proliferation. We concluded that edema fluid capable of cell-mediated immune suppression forms early after thermal injury and that lymph generated from the site of burn injury is immunosuppressive.

Animals↗
PubMedDate not supplied

Modulation of microvascular permeability by 21-aminosteroids after burn injuries.

Burn injuries initiate lipid peroxidation in capillary endothelial cells and cause alterations in microvascular permeability, with subsequent leakage of fluid and protein from the plasma into the interstitium. We evaluated the effects of two lazaroid compounds (U74389F and U75412E) on alterations in microvascular permeability that resulted from burn injuries. A canine model was used for the evaluation of microvascular permeability at the site of the burn injury with the use of a measure of the reflection coefficient (sigma(d)). Hindpaw lymph flow, lymph and plasma total protein concentrations, and arterial, venous, and capillary pressures were measured before burn injuries and for 6 hours in 6 different groups. Footpaw weight gain was then calculated as the percentage of increase of experimental hindpaw relative to the contralateral paw. The damage was attenuated by 20 mg/kg of lazaroid U75412E given before the injuries, but a lower dose was not effective. This agent was also effective in limiting edema formation, as evidenced by changes in footpaw weight gain. However, the administration of either lazaroid compound produced no significant effect on the burn-induced changes in capillary permeability. We conclude that these lazaroids do not prevent burn-induced changes in permeability at the site of injury when administered after an injury. U75412E administered before the injury was effective in limiting the alterations in microvascular permeability.

Animals↗
PubMedDate not supplied

Development of a protocol to provide prolonged general anesthesia to pregnant sows.

This study was designed to determine whether a pregnant sow could be maintained under conditions of prolonged general anesthesia in order to provide access to prematurely delivered piglets for purposes of acute experimentation. Fifteen time-dated pregnant (90% of gestation) sows were preanesthetized with intramuscular xylazine (Rompun Mobay Pharmaceutical, Shawnee, KS)/ketamine (Aveco Pharmaceutical, Fort Dodge, IA). After anesthesia was induced with intravenous sodium thiopental, the animals underwent tracheotomy and mechanical ventilation. The electrocardiogram was monitored externally; systemic arterial pressure was supervised by the insertion of a brachial artery cannula; and urine output was determined by inserting a cystostomy tube. A surgical plane of anesthesia was achieved by the "balanced" technique: an inhalant, isoflurane, supplemented by intravenous doses of sufentanil citrate, propofol (Stuart Pharmaceuticals, Wilmington, DE), and vecuronium. Sows were maintained under general anesthesia for an average of 12 h; piglets were delivered, one or two at a time, by a modified cesarean section technique. No sows or piglets were lost to anesthetic complications. It is concluded that, with appropriate precautions, pregnant sows can be anesthetized for a prolonged period of time, and provide viable premature neonates for acute experimentation.

Anesthesia, General↗
PubMedDate not supplied

Organ blood flow redistribution in response to hypoxemia in neonatal piglets.

This study was designed to determine the effects of severe hypoxemia on newborn piglet visceral blood flow. While the hemodynamic effects of a severe hypoxemic insult are well characterized in newborn animals, its impact on organ perfusion in premature infants is not well characterized. Cannulas were placed in the femoral vessels and left atrium of term (1-14 days old) and prematurely delivered (cesarean section at 90% of term gestation) piglets. After stabilization, some animals were subjected to 1 h of ventilator-controlled hypoxia (yielding PaO2 approximately = 30-40 torr) followed by 30 min of reoxygenation; the remaining animals served as unchallenged controls. Radiolabeled microspheres were injected in all animals at times 0 min (baseline), 5 and 60 min (hypoxia), and 90 min (reoxygenation). Blood flows (mL/min/g tissue) to organs were determined using reference organ techniques. Control animals displayed no alterations in any of the variables monitored. Throughout the experimental period, organ blood flows were almost uniformly lower (p<.05, ANOVA) in premature versus term animals. The trend toward increased cerebral and cardiac blood flows during hypoxia observed in the premature piglets was similar to that of term animals, but of lower magnitude. In term piglets, hypoxia produced an immediate and significant (*p<.05) decline in small-intestinal blood flow followed by autoregulatory escape (2.02+/-0.17 mL/min/g at time 0, 1.56+/-0.15 mL/min/g at 5 min hypoxia, 1.88+/-0.18 mL/min/g at 60 min hypoxia, 2.26+/-0.19 mL/min/g at 30 min reoxygenation), an effect not readily observed in the premature piglets (0.48+/-0.10 mL/min/g at time 0, 0.44+/-0.07 mL/min/g at 5 min hypoxia, 0.46+/-0.10 mL/min/g at 60 min hypoxia, 0.42+/-0.08 mL/min/g at 30 min reoxygenation). However, mucosal blood flows measured in these younger animals declined throughout the experimental period to almost 50% of baseline, compared to a complete restoration to baseline blood flow observed following reoxygenation of term piglets. Intestinal blood flow in premature infants is small when compared to term animals, and alterations in small intestinal blood mucosal flow induced by hypoxia appear less well tolerated by the premature animals. Taken together, this may in part account for the increased risk of developing intestinal ischemic diseases in premature infants who are even temporarily exposed to a severe hypoxic challenge.

Analysis of Variance↗
PubMedDate not supplied

Subeschar tissue fluid: a source of cell-mediated immune suppression in victims of severe thermal injury.

Thermal injury results in pronounced physiologic alterations in microcirculation at the site of tissue damage. The consequence of these changes is an increase in microvascular permeability, leading to the accumulation of tissue edema, or subeschar tissue fluid (STF). One of the adverse properties of edema is its capacity in vitro to inhibit cell-mediated immune function. Since previous studies evaluated STF collected 5 to 7 days after thermal injury, the present study was designed to determine the time frame during which STF demonstrates its immune suppressive nature. Seven patients with severe thermal injury (30% to 100% total body surface area) were entered into the study. STF was collected in serial fashion, beginning as early as 9 hours after injury and continuing until fascial excision or patient death (maximum of 139 hours after injury). The addition of STF to cultures of lymphocytes obtained from healthy donors resulted in complete inhibition of mitogen-induced lymphocyte proliferation (MILP). Serum collected concomitantly from this group of patients was also capable of inhibiting MILP. From its inception, STF possesses the ability to inhibit MILP; this suppressive nature is stable, persisting for prolonged periods of time. The gradual absorption of STF likely contributes to the serologic evidence of cell-mediated immune suppression documented in victims of severe thermal injury.

Adolescent↗